Electromagnetic friction device



y 1950 J. G. OETZEL 2,507,573

ELECTROMAGNETIC FRICTION DEVICE Original Filed Dec. 7, 1944 INVENTORJohn George 0et3e/ DY Q u ATTORNEYS Patented May 16, 1950-ELECTROMAGNETIC FRICTION DEVICE John George Oetzel, Beloit, Wis.,assignor to Warner Electric Brake Manufacturing Company.

South Beloit,

Original application Dec 567,004. Divided an ber 20, 1945, Serial 2Claims. 1

This invention relates to electromagnetic friction devices of the typecomprising axially engageable magnet and armature rings mounted forrelative rotation.

The object is to provide a novel and rugged mounting for the magnet ringin a device of the above character.

Other objects and advantages of the invention will become apparent fromthe following detailed description taken in conjunction with theaccompanying drawing which is a diametrical sectional view of theimproved friction device incorporated in a vehicle brake construction.

In the illustrated embodiment, the improved friction device is mountedwithin a brake drum i secured by screws 2 to a vehicle wheel 3 rotatableon an axle 4 having a flange 5 to which the anchor plate 6 of a brake issecured by screws 1. The friction device includes a substantially flatarmature ring 8 supported for yieldable axial floating movement. This isaccomplished by tangentially extending leaf springs 9 rigidly secured tothe vehicle wheel at one end by the screws 2, the other ends beingsecured to the back of the armature ring at annularly spaced points.Suitable stop means, not shown, is provided to sustain the frictionaltorque applied to the armature when this torque is in a direction tocompress the leaf springs. The latter, in addition to supporting thearmature, maintain the armature in continuous light mechanical contactwith the friction face of a magnet ring l0 which is mounted inaccordance with the present invention. This ring is of U-shaped crosssection having two concentric poles H and I! with an annular coil 13between them and se ments ll of friction material spanning the poles andsubstantially flush with the end faces thereof.

Herein, the magnet is formed by welding together in abutting relation acylinder forming the inner pole i2 and a ring I! of Z-shaped crosssection having a flange forming the outer pole II and a fiat annulus itagainst which the cylinder l2 abuts and is welded at IT. The innerperipheral portion of the annulus I8 is bent reversely to form a tubularprojection I 8 having an inturned flange l9. The latter is disposedbetween the anchor plate 0 and the end of a collar rigidly held betweenthe axleflange B and the wheel bearing 2|. The collar 20 provides abearing for a portion of the tubular extension It. the flange l9 havinga running fit between the anchor plate 8 and the collar 20. This rugged111., a corporation of Illinois ember 7, 1944, Serial No. (1 thisapplication Septem- No. 617,598

mounting supports the magnet for oscillation about the wheel axis, and,together with the flange i9, is well adapted to sustain the overhangingweight of the magnet under severe bending shocks. The angular motion ofthe magnet may be used through a connection with a pin 23 on the ring I6to expand a friction brake into engagement with the drum 1.

This application is a division of my co-pending application Serial No.567,004, filed December 7, 1944, now U. S. Patent No. 2,469,402.

I claim as my invention:

1. In an electromagnetic friction device, the combination of, a magneticring of Z-shaped radial cross section having an outer cylindricalportion, a fiat intermediate portion perpendicular to the ring axis anda tubular inner portion with an inturned right angular flange at the endthereof, a separately formed magnetic cylinder abutting against saidintermediate portion and cooperating with said first cylindrical portionto form the poles of a magnet, said tubular portion being ofiset axiallyfrom said magnet, bearing means engaging said tubular portion and saidflange and supporting the same for turning about the axis of said ring,and means bearing against opposite sides of said inturned flange tosupport said tubular portion against tilting under the offset weight ofsaid magnet.

2. In an electromagnetic friction device, the combination of, a sheetmetal ring having an outer cylindrical portion, an intermediate portionsubstantially perpendicular to the ring axis and a tubular inner portionaxially offset from said cylindrical portion, means cooperating with theouter portion of said ring to form a magnet having concentric poles,bearing means engageable with said tubular portion and supporting thesame for turning about the axis of said ring, and means engaging theopposite sides oi. said inturned flange to hold said tubular portionagainst axial tilting.

JOHN GEORGE OETZEL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 347,075 Timmis et a1. Aug. 10,1888 1,822,564 Cadman Sept. 8, 1931 1,858,424 Perrot May 3, 1932

